This document details the analysis of farm survey data taken pre and post COVID 19.
The overall effect on the labour numbers:
Farms with more staff: 1
Farms with less staff: 32
Farms with the same number of staff employed: 7
So most farms reported a decrease in employee numbers. The mean change in employee number was -1.5 and the median change was -1.5.
Before COVID19 the farms employed 76 permanent staff, 81 seasonal staff and 52 non-technical staff.
After COVID19 the farms employed 49 permanent staff, 81 seasonal staff and 19 non-technical staff.
Difference in permanent staff numbers: -27
Difference in seasonal staff numbers: 0
Difference in non-technical staff numbers: -33
The effect was appears to be a reduction in permanent and non-technical staff numbers with seasonal numbers remaining consistent. However, it is a little more complicated than that.
For example, of all the farms 19 reduced permanent staff, 0 increased permanent staff and 21 kept the same number of permanent staff.
INPUT THE RANGE OF VALUES.
Those farms that reduced permanent staff did so by a mean of -1.4210526 employees with a median of -1 and a range of -3 to -1. Those farms that increased permanent staff did so by a mean of NaN employees with a median of NA.
For seasonal staff, of all the farms 12 reduced seasonal staff, 11 increased seasonal staff and 17 kept the same number of seasonal staff.
Those farms that reduced seasonal staff did so by a mean of -1 employees with a median of -1 and a range of -1 to -1. Those farms that increased seasonal staff did so by a mean of 1.0909091 employees with a median of 1.
For non-technical staff, of all the farms 25 reduced non-technical staff, 0 increased non-technical staff and 15 kept the same number of non-technical staff.
Those farms that reduced non-technical staff did so by a mean of -1.32 employees with a median of -1 and a range of -2 to -1. Those farms that increased non-technical staff did so by a mean of NaN employees with a median of NA.
The trend in seasonal staff was either a reduction or increase by a single employee, or no change occurring. Of those 11 farms increasing the seasonal staff, 10 farms had decreased their permanent staff, 8 farms had decreased their non-technical staff, and 8 reduced both permanent and non-technical staff. 1 farms kept the same number of permanent staff, and 3 kept the same number of non-technical staff, and 1 kept the same number of permanent and non-technical staff, whilst increasing seasonal employees.
The overall effect on the labour costs:
The mean labour cost pre-COVID was 3.9284789 and was 3.5214706 post-COVID suggesting a small decrease in labour cost due to COVID. For each of the employment types the means were:
Pre-covid Permanent Labour cost mean: 3.7031034
Post-covid Permanent Labour cost mean: 3.5927586
Pre-covid Seasonal Labour cost mean: 4.232
Post-covid Seasonal Labour cost mean: 3.7529032
Pre-covid Non-technical Labour cost mean: 3.8503333
Post-covid Non-technical Labour cost mean: 3.21875
Therefore, there has been reduction in all employment sector costs due to COVID. These values are the costs per employee and therefore this suggests a decrease in the wages for sector employees.
Assuming the costs are normally distributed (which is a fair assumption to make) we can check whether there is a statistical difference between the costs per employee. This will be a pairwise test using farms with before and after data.
To test whether there was a significant difference in the costs per employee pre and post COVID 19 a one-tailed paired t-test was performed on the data.
For permanent employee costs:
P-value: 0.1872952
Test Statistic: -0.9023074
Degrees of Freedom: 28
Estimated difference in means: -0.1103448
For seasonal employee costs:
P-value: 2.013102910^{-6}
Test Statistic: -5.6633117
Degrees of Freedom: 29
Estimated difference in means: -0.504
For non-technical employee costs:
P-value: 0.0019174
Test Statistic: -3.4153766
Degrees of Freedom: 15
Estimated difference in means: -0.48375
The results suggest a significant decrease in the costs of labour for seasonal and non-technical employees with a decrease of 0.5USD per day (-0.504 for seasonal staff and -0.48375 for non-technical staff). There was no significant difference in the costs for permanent staff.
Here the effect of COVID19 is explored on the labour used to run the farms.
And, combined into a subplot
These results suggest:
The total mean farm labour costs (cost per type of worker x number of workers) was 20.45875 per day pre-covid19 compared to 13.274 per day post-covid19.
For each type of employment sector this is broken down into:
Permanent staff Pre-covid Mean total cost: 9.4827586 Permanent staff Post-covid Mean total cost: 5.8803448
Seasonal staff Pre-covid Mean total cost: 10.022 Seasonal staff Post-covid Mean total cost: 9.7351613
Non-technical staff Pre-covid Mean total cost: 6.4193333 Non-technical staff Post-covid Mean total cost: 3.665
In the following diagram the difference in total staff numbers and the difference in the total cost of labour (cost of labour x number of employees) is plotted as a bubble chart. On this chart the size of the bubble reflects the total labour cost pre-COVID19 and the colour of the bubble the total labour cost post-COVID19. Therefore a large bubble that is coloured black reflects a farm with a relatively large pre-COVID19 labour cost and a large post-COVID19 labour cost. In contrast a small bubble with a white colour has a low pre- and post-COVID 19 labour cost.
The plot suggests that farms with larger costs pre-COVID19 reduced their staff numbers more resulting in relatively lower post-COVID19 costs.
Also have created some dumbbell plots to show the change in labour costs pre and post covid. Here as a combined plot
And, here as single plots.
Prior to covid19 the mean gate prices for fish were:
Pangasius: 88.8787879 +/- 3.6636523
Tilapia: 80.0285714 +/- 4.1902247
Carp: 116.8518519 +/- 6.5263001
Other catfish: 282.8571429 +/- 22.5989886
After covid19 the mean gate prices for fish were:
Pangasius: 80.2121212 +/- 3.764618
Tilapia: 74.4 +/- 3.9719605
Carp: 103.5185185 +/- 7.4439979
Other catfish: 249.7142857 +/- 21.7588
The percentage increase in prices were:
Pangasius: -10.8046845
Tilapia: -7.5652842
Carp: -12.8801431
Other catfish: -13.2723112
There were 33 pangasius farms with pre & post-COVID gate prices, 35 tilapia farms with pre & post-COVID gate prices, 27 carp farms with pre & post-COVID gate prices and 35 other catfish farms with pre & post-COVID gate prices.
To test if the decrease was statistically significant a pairwise Student’s T-test was performed on the data with a single-tail (decrease).
For pangasius gate prices:
P-value: 1.54326110^{-18}
Test Statistic: -17.9078203
Degrees of Freedom: 32
Estimated difference in means: -8.6666667
For tilapia gate prices:
P-value: 3.462543310^{-15}
Test Statistic: -13.1453673
Degrees of Freedom: 34
Estimated difference in means: -5.6285714
For carp gate prices:
P-value: 3.219236410^{-14}
Test Statistic: -14.4222051
Degrees of Freedom: 26
Estimated difference in means: -13.3333333
For other catfish gate prices:
P-value: 9.996009210^{-24}
Test Statistic: -24.9236172
Degrees of Freedom: 34
Estimated difference in means: -33.1428571
The gate prices were plotted as scatter plots of pre- and post covid 19 prices. This shows whether there is price deflation or inflation due to the pandemic. Will look at putting together with the consumer prices.
Prior to covid19 the mean consumer prices for fish were:
Pangasius: 113.3471074 +/- 8.4011019
Tilapia: 125.9090909 +/- 10.1857744
Carp: 156.4876033 +/- 8.8186504
Other catfish: 415.7024793 +/- 25.8626644
After covid19 the mean Market prices for fish were:
Pangasius: 124.7107438 +/- 9.427299
Tilapia: 121.9421488 +/- 9.7119321
Carp: 177.0247934 +/- 13.3631725
Other catfish: 379.8347107 +/- 27.2407009
The percentage increase in prices were:
Pangasius: 9.1119947
Tilapia: -3.2531345
Carp: 11.6013072
Other catfish: -9.4429939
The consumer data was based on 15 Aratdar or Middlemen, 51 Paiker, or retailers, and 55 consumers.
For each category of merchandiser the values are:
Prior to covid19 the mean consumer prices for fish were:
Pangasius: 100 +/- 0
Tilapia: 109.3333333 +/- 3.7161168
Carp: 143.6666667 +/- 2.2886885
Other catfish: 378 +/- 4.1403934
After covid19 the mean MiddleMan prices for fish were:
Pangasius: 112.6666667 +/- 4.1690469
Tilapia: 108.6666667 +/- 4.8057505
Carp: 160.6666667 +/- 7.5277265
Other catfish: 349 +/- 3.8729833
The percentage increase in prices were:
Pangasius: 11.2426036
Tilapia: -0.6134969
Carp: 10.5809129
Other catfish: -8.3094556
Prior to covid19 the mean consumer prices for fish were:
Pangasius: 109.1176471 +/- 4.765069
Tilapia: 121.0784314 +/- 4.3947384
Carp: 151.6666667 +/- 4.5460606
Other catfish: 401.9607843 +/- 12.9645066
After covid19 the mean Retailer prices for fish were:
Pangasius: 119.8039216 +/- 6.8527939
Tilapia: 117.6470588 +/- 5.9458339
Carp: 171.372549 +/- 7.8789867
Other catfish: 364.9019608 +/- 17.1607167
The percentage increase in prices were:
Pangasius: 8.9198036
Tilapia: -2.9166667
Carp: 11.4988558
Other catfish: -10.1558302
Prior to covid19 the mean consumer prices for fish were:
Pangasius: 120.9090909 +/- 3.3459358
Tilapia: 134.9090909 +/- 5.3134098
Carp: 164.4545455 +/- 4.4796585
Other catfish: 438.7272727 +/- 14.6001707
After covid19 the mean Consumer prices for fish were:
Pangasius: 132.5454545 +/- 4.8945101
Tilapia: 129.5454545 +/- 6.7544723
Carp: 186.7272727 +/- 11.1479188
Other catfish: 402.0909091 +/- 19.8300863
The percentage increase in prices were:
Pangasius: 8.7791495
Tilapia: -4.1403509
Carp: 11.9279455
Other catfish: -9.1114628
Based on the mean gate prices and the mean selling price the mark up of the product was calculated.
Mark up of the mean price of pangasius was:
Pre-covid: 27.5299879 %
Post-covid: 55.4761823 %
Diff: 27.9461944 %
Mark up of the mean price of Tilapia was:
Pre-covid: 57.3301743 %
Post-covid: 63.9007376 %
Diff: 6.5705633 %
Mark up of the mean price of carp was:
Pre-covid: 33.9196605 %
Post-covid: 71.0078505 %
Diff: 37.08819 %
Mark up of the mean price of other catfish was:
Pre-covid: 46.965523 %
Post-covid: 52.1077217 %
Diff: 5.1421987 %
And, for each of the category of sellers.
Mark up of the mean price of pangasius was:
Pre-covid: 12.5127855 %
Post-covid: 40.4608991 %
Diff: 27.9481136 %
Mark up of the mean price of Tilapia was:
Pre-covid: 36.6178746 %
Post-covid: 46.0573477 %
Diff: 9.4394731 %
Mark up of the mean price of carp was:
Pre-covid: 22.9477021 %
Post-covid: 55.2057245 %
Diff: 32.2580224 %
Mark up of the mean price of other catfish was:
Pre-covid: 33.6363636 %
Post-covid: 39.7597254 %
Diff: 6.1233618 %
Mark up of the mean price of pangasius was:
Pre-covid: 22.7713042 %
Post-covid: 49.3588746 %
Diff: 26.5875704 %
Mark up of the mean price of Tilapia was:
Pre-covid: 51.2940056 %
Post-covid: 58.1277672 %
Diff: 6.8337616 %
Mark up of the mean price of carp was:
Pre-covid: 29.7939778 %
Post-covid: 65.5477218 %
Diff: 35.753744 %
Mark up of the mean price of other catfish was:
Pre-covid: 42.107348 %
Post-covid: 46.1277875 %
Diff: 4.0204395 %
Mark up of the mean price of pangasius was:
Pre-covid: 36.0381862 %
Post-covid: 65.2436721 %
Diff: 29.2054859 %
Mark up of the mean price of Tilapia was:
Pre-covid: 68.5761579 %
Post-covid: 74.1202346 %
Diff: 5.5440767 %
Mark up of the mean price of carp was:
Pre-covid: 40.7376459 %
Post-covid: 80.3805497 %
Diff: 39.6429038 %
Mark up of the mean price of other catfish was:
Pre-covid: 55.1056015 %
Post-covid: 61.0203869 %
Diff: 5.9147855 %
To test if differences in prices were statistically significant a pairwise Student’s T-test was performed on the data with two-tails.
For pangasius Market prices:
P-value: 2.437036810^{-55}
Test Statistic: 28.552012
Degrees of Freedom: 120
Estimated difference in means: 11.3636364
For tilapia Market prices:
P-value: 7.637637810^{-13}
Test Statistic: -8.0274555
Degrees of Freedom: 120
Estimated difference in means: -3.9669421
For carp Market prices:
P-value: 1.848863910^{-50}
Test Statistic: 25.6064263
Degrees of Freedom: 120
Estimated difference in means: 20.5371901
For other catfish Market prices:
P-value: 2.039935710^{-69}
Test Statistic: -38.528341
Degrees of Freedom: 120
Estimated difference in means: -35.8677686
During the process, the selling of the produce may exist as a value chain going from:
Farm >> MiddleMan >> Retailer >> Consumer
In this case, we can compare the mean prices at each stage to deduce the incremental price increases made at each step before and after COVID 19.
The mean price difference for stage 1 Pangasius: Pre-COVID is: 11.1212121 or 12.5127855%
Post-COVID is: 32.4545455 or 40.4608991% And the difference in markup for stage 1 is:
21.3333333 or a markup percentage change of: 27.9481136%
The mean price difference for stage 2 Pangasius: Pre-COVID is: 9.1176471 or 9.1176471%
Post-COVID is: 7.1372549 or 6.3348416%
And the difference in markup for stage 2 is:
-1.9803922 or a markup percentage change of: -2.7828054%
The mean price difference for stage 3 Pangasius: Pre-COVID is: 11.7914439 or 10.806175%
Post-COVID is: 12.741533 or 10.6353221%
And the difference in markup for stage 3 is:
0.9500891 or a markup percentage change of: -0.1708528%
The mean price difference for stage 1 Tilapia: Pre-COVID is: 29.3047619 or 36.6178746%
Post-COVID is: 34.2666667 or 46.0573477% And the difference in markup for stage 1 is:
4.9619048 or a markup percentage change of: 9.4394731%
The mean price difference for stage 2 Tilapia: Pre-COVID is: 11.745098 or 10.7424677%
Post-COVID is: 8.9803922 or 8.2641646%
And the difference in markup for stage 2 is:
-2.7647059 or a markup percentage change of: -2.4783032%
The mean price difference for stage 3 Tilapia: Pre-COVID is: 13.8306595 or 11.4228929%
Post-COVID is: 11.8983957 or 10.1136364%
And the difference in markup for stage 3 is:
-1.9322638 or a markup percentage change of: -1.3092565%
The mean price difference for stage 1 Carp: Pre-COVID is: 26.8148148 or 22.9477021%
Post-COVID is: 57.1481481 or 55.2057245%
And the difference in markup for stage 1 is:
30.3333333 or a markup percentage change of: 32.2580224%
The mean price difference for stage 2 Carp: Pre-COVID is: 8 or 5.5684455%
Post-COVID is: 10.7058824 or 6.6634123%
And the difference in markup for stage 2 is:
2.7058824 or a markup percentage change of: 1.0949668%
The mean price difference for stage 3 Carp: Pre-COVID is: 12.7878788 or 8.4315684%
Post-COVID is: 15.3547237 or 8.9598502%
And the difference in markup for stage 3 is:
2.5668449 or a markup percentage change of: 0.5282818%
The mean price difference for stage 1 OtherCat:Pre-COVID is: 95.1428571 or 33.6363636%
Post-COVID is: 99.2857143 or 39.7597254%
And the difference in markup for stage 1 is:
4.1428571 or a markup percentage change of: 6.1233618%
The mean price difference for stage 2 OtherCat: Pre-COVID is: 23.9607843 or 6.3388318%
Post-COVID is: 15.9019608 or 4.5564358%
And the difference in markup for stage 2 is:
-8.0588235 or a markup percentage change of: -1.7823961%
The mean price difference for stage 3 OtherCat: Pre-COVID is: 36.7664884 or 9.1467849%
Post-COVID is: 37.1889483 or 10.1914904%
And the difference in markup for stage 3 is:
0.4224599 or a markup percentage change of: 1.0447055%
The first production cost to be considered was the feed cost.
Prior to covid19 the mean feed prices for fish were:
Pangasius: 39.6363636 +/- 2.8811693
Tilapia: 35.9444444 +/- 2.401719
Carp: 28.1071429 +/- 2.6435006
Other catfish: 50.8055556 +/- 4.1666667
After covid19 the mean Consumer prices for fish were:
Pangasius: 42.4848485 +/- 2.7170896
Tilapia: 38.8285714 +/- 2.6732412
Carp: 31.6923077 +/- 2.4943012
Other catfish: 55.3714286 +/- 4.3188078
The percentage increase in prices were:
Pangasius: 6.7047076
Tilapia: 7.4278473
Carp: 11.3124133
Other catfish: 8.2459007
The increase per kg on average in prices were:
Pangasius: 2.8484848
Tilapia: 2.884127
Carp: 3.5851648
Other catfish: 4.565873
To test if differences in prices were statistically significant a pairwise Student’s T-test was performed on the data with two-tails.
For pangasius Market prices:
P-value: 5.978559310^{-13}
Test Statistic: 11.5487482
Degrees of Freedom: 32
Estimated difference in means: 2.8484848
For tilapia Market prices:
P-value: 1.607350410^{-15}
Test Statistic: 13.8294796
Degrees of Freedom: 34
Estimated difference in means: 2.9428571
For carp Market prices:
P-value: 5.674759610^{-16}
Test Statistic: 18.2661567
Degrees of Freedom: 25
Estimated difference in means: 3.7307692
For other catfish Market prices:
P-value: 1.643895210^{-17}
Test Statistic: 16.1435865
Degrees of Freedom: 34
Estimated difference in means: 4.4
The second production cost to be considered was the medicine cost.
Prior to covid19 the mean medicine prices for fish were:
Pangasius: 1.684848510^{4} +/- 3914.0868357
Tilapia: 2.168571410^{4} +/- 4470.6324633
Carp: 3.976923110^{4} +/- 7382.7241168
Other catfish: 4.422857110^{4} +/- 6449.2850232
After covid19 the mean medicine prices for fish were:
Pangasius: 1.990909110^{4} +/- 4002.839901
Tilapia: 2.328571410^{4} +/- 5244.4448401
Carp: 4.330769210^{4} +/- 8943.2398191
Other catfish: 4.751428610^{4} +/- 6554.6186167
The percentage increase in prices were:
Pangasius: 15.3729072
Tilapia: 6.8711656
Carp: 8.1705151
Other catfish: 6.9152135
The increase per kg on average in prices were:
Pangasius: 3060.6060606
Tilapia: 1600
Carp: 3538.4615385
Other catfish: 3285.7142857
To test if differences in prices were statistically significant a pairwise Student’s T-test was performed on the data with two-tails.
For pangasius Market prices:
P-value: 6.006014210^{-17}
Test Statistic: 16.16
Degrees of Freedom: 32
Estimated difference in means: 3060.6060606
For tilapia Market prices:
P-value: 6.015655410^{-6}
Test Statistic: 5.3508484
Degrees of Freedom: 34
Estimated difference in means: 1600
For carp Market prices:
P-value: 0.0017434
Test Statistic: 3.5050226
Degrees of Freedom: 25
Estimated difference in means: 3538.4615385
For other catfish Market prices:
P-value: 6.863918810^{-10}
Test Statistic: 8.4684422
Degrees of Freedom: 34
Estimated difference in means: 3285.7142857
The next production cost to be considered was the total production cost. this has been confirmed to include feed and medicines.
Prior to covid19 the mean total production prices for fish were:
Pangasius: 71.5714286 +/- 2.7470381
Tilapia: 71.1714286 +/- 3.6338742
Carp: 92.2580645 +/- 3.6965546
Other catfish: 170.7142857 +/- 17.0700485
After covid19 the mean total production prices for fish were:
Pangasius: 78.5454545 +/- 3.4103785
Tilapia: 76.5142857 +/- 3.92107
Carp: 105.7407407 +/- 6.460487
Other catfish: 199.1428571 +/- 17.8838456
The percentage increase in prices were:
Pangasius: 8.8789683
Tilapia: 6.982823
Carp: 12.7506921
Other catfish: 14.2754663
The increase per kg on average in prices were:
Pangasius: 6.974026
Tilapia: 5.3428571
Carp: 13.4826762
Other catfish: 28.4285714
To test if differences in prices were statistically significant a pairwise Student’s T-test was performed on the data with two-tails.
For pangasius Market prices:
P-value: 1.871913710^{-22}
Test Statistic: 24.7841466
Degrees of Freedom: 32
Estimated difference in means: 7.030303
For tilapia Market prices:
P-value: 8.411981210^{-16}
Test Statistic: 14.1406252
Degrees of Freedom: 34
Estimated difference in means: 5.3428571
For carp Market prices:
P-value: 5.000838710^{-15}
Test Statistic: 16.0811884
Degrees of Freedom: 26
Estimated difference in means: 13.4444444
For other catfish Market prices:
P-value: 7.226973710^{-21}
Test Statistic: 20.7273146
Degrees of Freedom: 34
Estimated difference in means: 28.4285714
The profit margin is the profit (Gate Price minus the Total Production Costs). Net profit margin = net profit/revenue or (revenue - cost)/revenue
The gross margin was considered.
Prior to covid19 the mean gross margin for fish were:
Pangasius: 0.1937756 +/- 0.0502693
Tilapia: 0.1085396 +/- 0.061562
Carp: 0.2065708 +/- 0.0549086
Other catfish: 0.3943008 +/- 0.0620942
After covid19 the mean gross margin for fish were:
Pangasius: 0.0181513 +/- 0.0712717
Tilapia: -0.0306449 +/- 0.0674317
Carp: -0.0268962 +/- 0.0919104
Other catfish: 0.1985559 +/- 0.0833642
The percentage increase in gross margins were:
Pangasius: -967.5571653
Tilapia: 454.1849268
Carp: 868.0289705
Other catfish: -98.5842983
The increase per kg of average gross margin were:
Pangasius: -0.1756243
Tilapia: -0.1391845
Carp: -0.2334671
Other catfish: -0.1957449
To test if differences in prices were statistically significant a pairwise Student’s T-test was performed on the data with two-tails.
For pangasius Market prices:
P-value: 7.413459510^{-22}
Test Statistic: -23.6868711
Degrees of Freedom: 32
Estimated difference in means: -0.1756243
For tilapia Market prices:
P-value: 2.90719210^{-22}
Test Statistic: -22.9318901
Degrees of Freedom: 34
Estimated difference in means: -0.1391845
For carp Market prices:
P-value: 8.571224110^{-17}
Test Statistic: -19.800034
Degrees of Freedom: 25
Estimated difference in means: -0.2334671
For other catfish Market prices:
P-value: 8.759003810^{-24}
Test Statistic: -25.5680962
Degrees of Freedom: 34
Estimated difference in means: -0.1957449